Turbobike Web Site www.Turborick.com

Re: [turbobike] Carb Question

Bryan (bgoodwin@iquest.net)
Mon, 22 Nov 1999 17:38:04 -0500

Christer, I'm not sure about your reference to draw through kits and the
significance of airbox size.





At 10:38 PM 11/22/99 +0100, Christer Johansson wrote:
>Yes it is insignificant, just have a look at the draw through kits ,like
>Mr turbo, almost no plenum and no pipes ,intercooler.
>But in normally aspirated mode , this is a restriction, hence the
>priority breather valve. B.t.w Im working on My own version
>of the priority valve , Im using a 2 stroke reed valve, has anybody
>tried this before?
>
>Christer
>
>shammar@nsk-corp.com skrev:
>
>> Don't worry: we like counter-discussion.  That's the point of this
forum.  I do
>> think that Abraham is onto something.  I believe that the amount of time
it will
>> take to fill the plenum will be insignificant.
>>
>> Bryan <bgoodwin@iquest.net> on 11/22/99 12:26:04 PM
>>
>> To:   Bob Shammas/EQA/Nsk-Corp@Nsk-Corp
>> cc:   FFDennis@aol.com, turbobike@natvideo.com
>> Fax to:
>> Subject:  Re: [turbobike] Carb Question
>>
>> Bob, I realilze that boost response and timing is primarily controlled by
>> the turbine sizing. However, that assuming all else equal. Given a fixed
>> A/R on the turbine, increasing the size of the plenum volume will increase
>> the time it takes to fill it. What I'm not sure of is how dramatic an
>> effect this will have.
>>
>> P.S. Not trying to argue, just making friendly counter-discussion. :)
>>
>> At 07:49 AM 11/22/99 -0500, shammar@nsk-corp.com wrote:
>> >
>> >Realistically you'll never get too much plenum volume.  The need for
plenum
>> >volume is all but forgotten on four cylinder engines since the intake
>> events of
>> >the cylinders provide an almost uninteruppted flow out of the compressor.
>> >However, a larger accumulator volume reduces manifold pressure
fluctuations
>> >between intake events.  On a twin, you'll run into surge much more
easily and
>> >must have a huge plenum.  Having a large plenum is akin to being able to
>> blow up
>> >a balloon with full lungs the whole time.  You don't want empty lungs
>> before the
>> >intake valve event has finished.
>> >
>> >Turbine response (how fast it makes boost) will be governed by the exhaust
>> event
>> >and turbocharger matching.
>> >
>> >That's just my $0.02.  I've built a few bikes but that doesn't mean
anything
>> >either.
>> >
>> >Bob
>> >
>> >
>> >
>> >
>> >
>> >
>> >Bryan <bgoodwin@iquest.net> on 11/21/99 01:37:26 PM
>> >
>> >To:   FFDennis@aol.com, turbobike@natvideo.com
>> >cc:    (bcc: Bob Shammas/EQA/Nsk-Corp)
>> >Fax to:
>> >Subject:  Re: [turbobike] Carb Question
>> >
>> >
>> >
>> >I think the only problem you would run into there is that the volume of
the
>> >airbox would be too large. This might cause the turbo to boost later.
>> >
>> >
>> >
>> >
>> >At 10:38 AM 11/21/99 EST, FFDennis@aol.com wrote:
>> >>In a message dated 11/19/1999 23:56:32 Central Standard Time,
ABNZX9@aol.com
>> >>writes:
>> >>
>> >><< Now for another question how about intake plenum and attaching it
to CV
>> >> carbs?  Should I buy a set of velocity stack and machine them in
order to
>> >>fit
>> >> an intake plenum to the carbs that way?   I have a feeling that the
intake
>> >> plenum I am currently using is robbing me of effieciency.
>> >>  >>
>> >>
>> >>You raise another interesting possibility.....If you can encapsulate the
>> >>entire carburetor within a plenum, and then pressurize the entire plenum,
>> >you
>> >>eliminate the need for separate pressurization lines for bowl vents, CV
>> >slide
>> >>vents, etc., as you would have equal pressure operating on all sides
of the
>> >>crab.  The pressure in the venturi would be lower than the other areas,
>> >which
>> >>is how a carb works.  Your next problem is then to seal the throttle
cables
>> >>and fuel lines where they pass into the plenum.  I've seen ram air setups
>> >>like this.  It seems to me that a turbo plenum could get away with being
>> >less
>> >>aerodynamic internally due to the mechanical pressurization.
>> >>
>> >>Just my .02.........lots of book knowledge and reading, I've never
built a
>> >>turbo bike (but I have a KZ 900 motor in pieces, bead blasted, for a
future
>> >>project......)
>> >>
>> >>Dennis
>> >>'99 M2 Cyclone
>> >>'87 KLR 650 Urban Assault Vehicle
>> >>'78 KZ900 bike in boxes
>> >>
>> >>
>> >bgoodwin@iquest.net
>> >FZR1000 turbo EFI
>> >(aka The Money Pit)
>> >
>> >
>> >
>> >
>> >
>> >
>> bgoodwin@iquest.net
>> FZR1000 turbo EFI
>> (aka The Money Pit)
>
>
>
>
>
bgoodwin@iquest.net
FZR1000 turbo EFI
(aka The Money Pit)